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Continuing the Development of Reduced Density
Composites (SMC) for Automotive Applications
Presentation at SPE ACCE 2011Troy, MI
SPE ACCE 2011 – Troy, MI – September 13, 20110Creative � Reliable � Composites
September 13, 2011
Creative � Reliable � Composites
Terrence J. O’DonovanVP Marketing and Sales
Core Molding Technologies, Inc.
Presented by
Let’s buy a car . . .Let’s buy a car . . .
However, across large populations
worldwide, the following factors almost
Key buying factors depend strongly on individuals’ personal situations when
choosing whether to buy a car, and which model to purchase
SPE ACCE 2011 – Troy, MI – September 13, 20111Creative � Reliable � Composites
worldwide, the following factors almost always appear at the top of the list:
and of all the major consumer buying factors, Safety and Fuel economy are also regulated in the US to meet minimum standards
• Price
• Brand reputation
• Safety
• Fuel economy
• Styling
• Utility (features and benefits)
Improving fuel economy is important to OEMsImproving fuel economy is important to OEMs
The US “Corporate Average
Fuel Economy” (CAFE) defines
the minimum standards for
passenger vehicles
Recently approved increases
to CAFE minimums present
automobile OEMs a steep
challenge in coming years 15
20
25
30
35
40
CAFE
MPG
Average Fuel Economy of New US Passenger Cars
(MPG)
SPE ACCE 2011 – Troy, MI – September 13, 20112Creative � Reliable � Composites
challenge in coming years
The 2016 CAFE targets are
driving an improvement in
fuel economy of at least +20%With targets for 2025even higher
15
1980 1991 1994 1997 2000 2003 2006 2009 2012 2015
Sources: Bureau of Transportation Statistics, EPA.
LightweightingLightweighting works . . . but how much is needed?works . . . but how much is needed?
Reducing vehicle weight improves fuel
economy by reducing inertial forces
acting on the vehicle
Much research work has been done to validate the benefits of reducing weight and to model the impact to fuel economy
from weight reductions
SPE ACCE 2011 – Troy, MI – September 13, 20113Creative � Reliable � Composites
The range of impact is
10%
weightreduction
4-7%
MPGimprovement
To get 20% improvement in fuel economy purely from weight savings would require 30-35%
reduction in weight . . . on 3,800 lb vehicle, that’s a weight reduction of 1,200 lb
Weight reduction
is a
“big time”
SPE ACCE 2011 – Troy, MI – September 13, 20114Creative � Reliable � Composites
“big time”opportunity for the
automotive industry
Start with the “other DStart with the “other DMV”MV” to drive weight savingsto drive weight savings
Not the “Department of Motor Vehicles” but “Density,” “Mass” and “Volume”
density =mass
volume
mass = density x volume
Apply the Principle to the CarThe OEM Perspective
M = D • V
To reduce volume (V):
SPE ACCE 2011 – Troy, MI – September 13, 20115Creative � Reliable � Composites
Save weight by
• Lowering volume
• Lowering density
To reduce volume (V):
• downsize the car
• redesign to eliminate
components
To reduce density (D):
• substitute materials that
have lower densities
COMPOSITES!
Where will the weight reduction come from?Where will the weight reduction come from?
From every
vehicle system . . .
Body
40%
Chassis
24%
Powertrain
16%
Interior
15%
Electrical systems
5%
Vehicle mass distributionby subsystem
SPE ACCE 2011 – Troy, MI – September 13, 20116Creative � Reliable � Composites
. . . and every material contributor
24%
Source: L. Cheah, PhD Thesis, MIT, September, 2010, p. 34.
Approximate material compositionof a typical automobile in the U.S.
Carbon
steel
44%
High-strength steel, 12%
Plastics and composites,8%
Other
21%
Iron, 8%
Aluminum, 7%
1945 First automobile developed with a
fiberglass composite body
1953 MFG launches the Corvette fiberglass body
1954 Thunderbird has a composite hardtop
1960 Sheet molding compound (SMC) invented
1968 Chrysler station wagon introduced with an
SMC rear air deflector
1970 Pontiac Tempest one-piece grille opening showcases
SMC’s ability to consolidate parts and reduce weight
Composites Composites –– and SMC and SMC –– have earned a place at the tablehave earned a place at the table
Brief history of composite applications in the US automobile industry
SPE ACCE 2011 – Troy, MI – September 13, 20117Creative � Reliable � Composites
SMC’s ability to consolidate parts and reduce weight
1972 Corvette body panels are converted to SMC
1981 Composite leaf spring introduced on the Corvette
1987 Mercury tracer bumper beam becomes the first SMC structural part on an automobile in North
America
1996 Ford introduces SMC front-end system on Taurus and Sable
2003 “Tough Class-A” SMC improves surface quality on painted parts
2004 “Ultra Low Density” SMC is developed with hollow glass microspheres for a sunroof application
2007 Nano-Lite® SMC introduced as a 1.55 sp.gr. density SMC for vehicle body panels
Sources: Automotive Composites Alliance website; Plastics Technology, Oct. 2005
The advantages of composites are well knownThe advantages of composites are well known
• High strength (esp. stiffness) to weight ratio
• Ability to consolidate multiple components into a single molding
SPE ACCE 2011 – Troy, MI – September 13, 20118Creative � Reliable � Composites
• Highly corrosion resistant
• Can handle intricate and complex geometry
Typical “standard density” SMC has three components*Typical “standard density” SMC has three components*
Glass 30%2.6
Resin 25%1.0 1.9
Component Composition
Density(g/cm3)
SPE ACCE 2011 – Troy, MI – September 13, 20119Creative � Reliable � Composites
Resin 25%1.0
Filler 45%2.7
1.9g/cm3
Densities and composition represent a “generic” SMC for illustrative
purposes. In practice, density of individual components varies, and
SMC compositions can differ markedly from the generic mix shown.
*
Applying the density, mass, volume principle to SMCApplying the density, mass, volume principle to SMC
Glass 2.6
Resin 1.0
Filler 2.7
Density reminder
Reduce SMC part weight
M = D • V
Increase SMC strength to allow part design to accomplish objectives with less material volume
Alter the SMC components to reduce density without compromising mechanical properties
Idea/opportunity Consequence
� Lower the glass content � Immediate negative impact
on strength
� Lower the filler content � Reduces surface quality and
impact strength; increases
cost and worsens shrinkage
Idea/opportunity Consequence
� Replace glass fibers with
high-strength alternatives
(carbon, aramid or metal)
� Expensive and difficult to
process with current SMC
technology
� Introduce carbon
nanotubes or graphene
� Very expensive and difficult
to process with current
Strategy 2Strategy 1
SPE ACCE 2011 – Troy, MI – September 13, 201110Creative � Reliable � Composites
cost and worsens shrinkage
(dimensional control)
� Substitute other fibers for
glass
- polypropylene
- nylon
- agricultural (hemp,
jute, pecan shells)
� Beneficial impact on
density, but these
alternatives are difficult to
process with existing SMC
technology and equipment
and can limit strength
� Supplement/replace filler
with functional additives
- hollow glass
microspheres
- nanoclays
• Microspheres effective on
density, but reduce
strength, cost more, and
traditionally have presented
serious practical challenges
to part surface quality;
nanoclays effective, at cost
increase
nanotubes or graphene
platelets to the filler
to process with current
SMC technology – but, may
become more viable in the
future
What is needed . . .
A low-density, high-surface quality SMC
with mechanical properties comparable to
standard density material, and which is
SPE ACCE 2011 – Troy, MI – September 13, 201111Creative � Reliable � Composites
standard density material, and which is
economically viable for a wide variety of
automotive applications
A number of development constraints were selfA number of development constraints were self--imposedimposed
Development constraints on the low-density SMC program:
• Develop a tough material with improved stiffness to weight ratio
• Do not use hollow low-density fillers or spheres that can
potentially cause issues in customer finishing lines or high
water absorption in field applications
SPE ACCE 2011 – Troy, MI – September 13, 201112Creative � Reliable � Composites
• Stay within strict parameters for:
- cost
- mechanical properties
- surface quality
• Abandon systems quickly when they do not show potential to meet the design objectives
Comparison of mechanical Comparison of mechanical properties of low density properties of low density SMCsSMCs
Test Property1.43 Sp Gr
Material
Conventional 1.9
Sp Gr Class A
SMC
Earlier
developed 1.55
Sp Gr Class A
SMC
Tensile Strength, Mpa 79 90 85
(Strength : Weight)Tensile Str:
Sp Gr Ratio55.2 47.4 54.8
Tensile Modulus, Gpa 8.8 12.2 9.2
Flex Strength, Mpa 161 195 180
Flex Modulus, Gpa 8.2 11.8 8.9
Impact - Izod, Notched, J/m 1158 945 750
Property values are typical of production Property values are typical of production
lots and are not guarantees of performance.lots and are not guarantees of performance.
SPE ACCE 2011 – Troy, MI – September 13, 201113Creative � Reliable � Composites
Impact - Izod, Notched, J/m 1158 945 750
Impact- Reverse, in-lb 12 10 10
Water Absorption, % 0.38 0.41 0.8
Shrinkage, % 0.035 0.038 0.08
IMC Adhesion - Including 600
Hrs HumidityPass Pass Pass
Paint Adhesion, Hrs - per
customer SpecPass Pass Pass
Structtural Adhesive -
Customer spec - with Pliogrip
9100 system
Pass Pass Pass
Sp Gr 1.43 1.9 1.55
Glass % 29.8 29 34.5
Hardness 45 45 45
Poisson's ratio 0.303 0.31 Not conducted
CLTE, ppm/oC 26.81 18.51 23.6
ALSA Index 100 55 58
Creative � Reliable � CompositesSPE ACCE 2011 – Troy, MI – September 13, 201113
Benefits achieved by the new SMCBenefits achieved by the new SMC
• Delivers a 25% reduction in density overstandard SMC . . . and 8% reduction over
previous “best” available low-densityClass A SMC formulation
• Extremely tough . . . great for both
structural and appearance panel
applications
SPE ACCE 2011 – Troy, MI – September 13, 201114Creative � Reliable � Composites
• Does not include microspheres, allowing part surface
quality to be maintained throughout finishing operations
and downstream processing
• Economically viable for a range of automotive applications
• Demonstrates a 25% reduction in molding pressure, reducing wear and
tear on molding machines, seals and hydraulic systems
Application targets and the future for 1.43 density SMCApplication targets and the future for 1.43 density SMC
• Battery covers and trays
for electric vehicles
• Underbody shields (stone
guards, fender wells, etc.)
• Body panels
• Structural systems (door
Near-term application targets for low density SMC
SPE ACCE 2011 – Troy, MI – September 13, 201115Creative � Reliable � Composites
• Structural systems (door
frames, hood and trunk
reinforcements)
• Electric vehicle chassis
• Bumpers
• Oil pans, valve covers and
other engine components© Avi Abrams
Application targets and the future for 1.43 density SMCApplication targets and the future for 1.43 density SMC
• Further reduction of density below 1.43
• Continued improvement
of economics
Focus of future development work
SPE ACCE 2011 – Troy, MI – September 13, 201116Creative � Reliable � Composites
• Improving surface
quality without
sacrificing density
or strength
Creative � Reliable � Composites
SPE ACCE 2011 – Troy, MI – September 13, 201117Creative � Reliable � Composites
Creative � Reliable � Composites
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